OXO FLUORIDES OF TITANIUM AND VANADIUM - PREPARATION AND CRYSTAL-STRUCTURES OF [CP-ASTERISK-TIF(MU-O)]4 AND OVF2N=PPH3

The reaction of Cp*TiF3 (Cp* = C5Me5) (1) with O(SnBu3)2 affords the eight-membered ring compound [Cp*TiF-(mu-O)]4 (2) with elimination of Bu3SnF. This is the first example of an organometallic oxo fluoride of group 4 of the periodic table. The molecular structure of 2 has been determined by X-ray crystallography. It shows that the eight-membered ring is almost planar. The reaction of OVF3 with Ph3P=NSiMe3 yields OVF2N=PPh3 (3), which can be treated again with Ph3P=NSiMe3 to give OVF(N=PPh3)2 (4). The crystal structure of 3 shows that this compound is a monomer in the solid state. The oxo fluorides have characteristic differences in their structures or reactions compared to the corresponding chlorides.